00:00Welcome back to this lesson on OCI load balancer service.
00:08Let me just quickly talk about why you would use load balancer.
00:11You would use load balancer to achieve high availability and also achieve scalability.
00:17So, typically the way load balancer works is they are also referred to as reverse proxies.
00:21You would have a load balancer which would be used access by multiple clients, various clients.
00:29And these clients would hit the load balancer and the load balancer would proxy that traffic to the various backend servers.
00:38So, in this way it not only protects the various backend servers but also provides high availability in case a particular backend server is not available.
00:46The application can still be up and running and then it also provides scalability because if lots of clients start hitting the load balancer, you could easily add more backend servers.
00:58And there are several other advanced capabilities like SSL termination and SSL pass-through and lot of other advanced features.
01:07We are not getting into those because it is a foundational course but hopefully that gives you a good idea of what a load balancer does, the main benefits of using a load balancer.
01:15So, the first type of load balancer we have in OCI is a layer 7 load balancer.
01:20Layer 7 basically means it understands HTTP and HTTPS that is the OSI model and then there are various capabilities available here.
01:32So, the first thing is the load balancer comes in two different shapes.
01:35One is called a flexible shapes, a flexible shape where you define the minimum and the maximum and you define a range and your load balancer can achieve any kind of support any kind of traffic in that particular range going from 10 Mbps all the way to 8 Gbps.
01:53The second kind of shape is called dynamic where you pre-define the shapes.
01:57So, you have micro, small, medium, large and you pre-define the shape and you do not have to warm up your load balancer.
02:05If the traffic comes to that particular shape, the load balancer automatically scales.
02:10You can always do a public and a private load balancer.
02:14Public means load balancer is available on the web.
02:16Private means your multiple tiers like a web tier can talk to your database tier and balance the traffic between them but both tiers do not have to be public.
02:28Load balancer is highly available, highly scalable by design and it has lots of advanced features layer 7.
02:34Things like content based routing are supported and there is lots of other SSL features, other capabilities which this is being a foundational course.
02:44We are not getting into those but it has lots of rich features.
02:49The second kind of load balancer we have in OCI is called the network load balancer and as the name specify network load balancer operates at layer 4, layer 3 and layer 4.
03:00So, it understands TCP, UDP also supports ICMP.
03:05It is again like HTTP load balancer, it has both public and private options.
03:10So, you could create public network load balancer or private network load balancer.
03:14It is highly available, highly scalable, all those features are supported.
03:20Now, why would you use network load balancer over HTTP load balancer?
03:23The primary reason you would use it is it is much faster than HTTP load balancer.
03:30It has much lower latency.
03:31So, if performance is a key criteria for you, go with network load balancer.
03:36On the contrary, the HTTP load balancer has higher level intelligence because it can look at the packets, it can inspect the packets and it gets that intelligence.
03:47So, if you are looking for that kind of routing intelligence, then go with HTTP load balancer.
03:52So, just to recap, OCI provides you both layer 3 and layer 4 network load balancer as well as layer 7 HTTP load balancer with lots of advanced features.
04:04Thanks for watching.
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